Picture frame



FIG. 1 is a front elevation view of a picture frame showing my new design, the sides being shown broken to represent indeterminate length;

FIG. 2 is an elevation view of one side thereof, the opposite side being identical;

FIG. 3 is a rear elevation view thereof; and,

FIG. 4 is a typical cross-section of one side portion thereof. 

The ornamental design for a picture frame, as shown and described. 